Lock & Load

Maurice

The U.K. rx8 owners are anxiously awaiting the australian test of the canzoomer speciall as their E.C.U. ARE THE SAME AS THE OZ CARS AND THEY ARE KEEN ON , getting feed back from us , i am certain once feed back is given you will be snowed under with orders .

The next big stock tip may be in the canzoomer (maurice) modification industry shares.
Keep up the great work , kangarro 2.

michael

LL7

Given that you have driven both, how much louder is the Borla exhaust - especially in the under 5000 RPM range? If it makes the car sound like a riced out civic all the time it is not worth it - even for more power. Anyone have sound clip?

RIC SHAW

can anyone say how to overcome the dyno problem for rx8's. so a true reading is had.

O.R.A.

If you read this topic, you will see that, according to Canzoomer, there is no "dyno problem" for the RX-8.

What you see is what you get.

canzoomer

Not completely true.

To get dyno results you DO need to take some steps to [revent the car from getting a DSC error and resulting check engine condition. Not too hard to do, but takes SOME small efforts.

However I cansay I prefer to avoid dyno runs where possible.
It is hard on the car, and makes a lot of heat. On the road this is a lot more gentle to the car.

Lock & Load

MAURICE

As you mentioned i also prefer not to do dyno runs if not needed , however i am more than happy to do some to test the stage 1 kit down under , for the benefit of the AUSTRALIAN AND THE BRITISH CARS otherwise, putting my baby in streess full situations is a no no.

michael

canzoomer

After much work, trials and tribulations, we are now ready to ship to our patient customers!

https://www.rx8club.com/showthread.p...threadid=16692

Hymee

iTrader: (1)

L&L - Why are you adverse to a dyno? It is not really that different to doing a WOT acceleration in one gear on the road. For example, the runs we have done in the RX-8's have been in 4th gear, starting at 75km/h, ramping up the redline at almost 200km/h. The actual dyno run itself takes less than 20 seconds. Plus there is this friggin huge fan blowing fresh air (more like a gale force wind) into the nose of the car.

Some people have the mis-aprehension that a dyno run goes for a long period of time. Not true in the sorts of things we are talking about here. On an Engine Dyno doing a longevity test it might, but not a power run.

Cheers,
Hymee.

Lock & Load

HYMEE

Your explanation seems to make sense i had a different image of a dyno run as one putting my baby under duress , obviously i was mistaken .

Michael

Hymee

iTrader: (1)

Well - it puts is under some duress, but not really any more than what you put it under when you redline it in 4th gear. And as soon as max power/rpm is reached it is "all over" - throttle closed, and the brakes applied to slow things down again.

I'm glad I could help build a better understanding.

Cheers,
Hymee.

RobDickinson

The Uk and AUZ ECU maps are NOT the same.

UK cars are 170kw(231ps) maps for Euro stage4 emmisions.

AUZ cars are 177kw(240ps) maps for Euro Stage 3 emmisions.

Not the same.

But as a UK owner I am waiting to see how this all works out

adainty

Canzoomer, can you confirm if your improvments will work for the RX8 in the UK, should be picking up my car on January 2004 and want to find out how much money i will need to spend to get the car up to standard.

Lock & Load

Does anybody really know the real ECU outputs that have been placed in the rx8 in differing markets ?
Journalists here in australia are looking into the possibility that mazda has gilded the lilly and told us a whole bunch of B/S.
The rx8 does not feel like 177kw to me.

Hymee

iTrader: (1)

I am beginning to believe more and more about this "safe mode". I would like to point out the following though:

One problem in the Mazda argument was assuming all chassis dyno's are inertial based (the comment on load reducing as the engine reved faster).

Modern computerised electro-mechanical dyno's (like the one popular in Australia) do infact put load on the engine so as to determine the maximum tractive effort (equates to torque) at every RPM. From this the power is derived by simple matematical formulae. Power = torque x RPM (in appropriate units).

Another slight flaw. They say the only way to measure engine power is on an engine dyno. That part is correct. But on an engine dyno you still need your ECU hooked up, as it is what is controlling what is going on... So what about the wheels turning etc... when they are not even there. Then it hit me like a light bulb. Are you thinking what I'm thinking???

Instead of fooling the computer to think the front wheels are going the same speed at the rear wheels - why not disconnect the rear wheel sensors, and make the computer think the rear wheels are going the same speed as the front - 0 RPM???

Worth a thought anyway. I'll post my idea on another more related thread as well.

Cheers,
Hymee.

Racer X-8

0 rpm sounds like limp mode x 2 to me. I don't know what I'm talking about really, but the idea of paralleling the rear sensor inputs to the front ones to fool it into thinking that the front wheels are spinning @ rear wheel rpm is foolproof. How could that not work? Could 2 splitters be made to take the rear sensor cables & split them each into 2? Then connect the two cables out of each splitter to the front & rear inputs? Are the sensors simple 3-wire prox's or hall effects? PNP or NPN?

The ECU working with an engine dyno is another thing altogether. I dunno. Unless the ECU knows to ignore these inputs if all 4 are 0 rpm, that is a good one...

Maestro

I work for Mazda and Yes thats the official word.

Also putting on the 4WD dyno won't give a true reading either as the front wheels won't be moving so the ECU will retard timing and pump in more fuel as per 'Burnout / ********' mode :D

Hymee

iTrader: (1)

I did have a go at my theory. The ECU detects if the sensors are disconnected when the ignition is turned on. If not is displays ABS warning and the "car with wiggly lines" light - as per what happens on a Dyno. Also, when you do it to the back wheel sensors, the power steering faults out.

OK - What about this theory then: when they are on the Engine Dyno they send a "command sequence" to the ECU to take it out of ******** mode.

If we knew the command sequence we could send it via the OBDII port. No need to break into the wiring.

I do like the idea parralleling the signals, but impractical to do as a frequent excercise. The plugs for the sensors are in behind the inner gaurds as the front, and behind the boot/trunk lining in the rear.

If we found another connector that was easy to get to, we could put a breakout box in series, and jumper the front and rears.

Cheers,
Hymee.

canzoomer

The safe mode is very real.
I have personally encountered it several times.
Not really. It has nothing to do with engine dynamics.
It is the ABS and DSC unit that does this.

The unit is made by Bosch, and is the metal box next to the engine with the brake lines coming out of it, and the big cable harness going into it on a big latched connector.
About half the wires in the harness are pairs of lines going to the wheel speed sensors at the 4 wheels.

These sensors are a magnetic core surrounded by a coil of windings.
The wheels have a notched wheel inboard that the sensor faces.
When the tooth passes by a small pulse is generated in the coil.
When the notch passes by it drops. If you look in the shop manaul, you see the test procedure for a scope to read tht waveform, and it's characteristics.

It also shows you how to test the sensors by measuirng their static electrical resistance.

The pulses are collected by the Bosch ABS unit, and it controls the ABS braking functions. IT also sends messages to the ECU, whci participates in the DSC function by cutting power in a skid condition. The ECU also monitors sensors on the front wheels which detect the steering angle.
When the Bosch unit detects that the front wheels are turning at a different rate than the back, and when the brakes are applied, it triggers the ABS behaviour of pulsing the brakes.
When it detects that the wheels are turning at differnt speeds, but no brakes it tells the ECU, which cuts power, to stop a skid. If the wheels are turned the ECU cuts more power than when in a straight line, and sooner.

If you disconnect the sensors, then when you start the car, or when the Bosch unit monitors the sensors, it detects a fault when it does not "see" the sensors, and tells the ECU, whcih cuts power, as it does not consider the car to be "safe" and turns on lights on the dash.
When the ECU can not succeed in fixing the differnce in speed between the wheels it decides that something has gone horribly wrong, and puts the engine into a low power output mode, and turns on a check engine light.
If you shut down the car, then drive normally for a while, it will turn off the light, resume normal operation, and store the fault event in the ECU memory.

So, simply disconnecting the sensors immediately causes a fault.
A clever fellow would say that one could simply simulate the resistance in the circuit by disconnecting the sensors, and adding resistors to the circuit to simulate the sensor, so it does not generate a fault at the power on self test (POST)

That clever fellow would be wrong (been there done that, have attractive T shirt)

It checks the circuits for more than that.

And the ECU does more than listen to the Bosch ABS/DSC computer for info about the fact that the car is moving.
It has other sensors on the engine and transmission.
Don't forget, for example, it monitors the speed toadjust the amount of force used in the electrically assisted steering unit.
It changes the assist depending on speed.

All in all a fiendishly clever and complicated system.
Of course Mazda, who have the code for the ECU unit, can turn off or adjust the ECU bahaviour at will, so they can do tests without this problem.

One can cause similar faults while not even on a dyno.
Many people up here where we get ice and snow have already triggered faults by spinning their tires for extended time when partially stuck on ice.

Some people have done drag strip burnouts to warm tires, and triggered the same thing.

In general, if you spin the back wheels for about 3 seconds at any decent difference in speed from the front, it will trigger an ECU event and check engine light.

Mazda provided a way to turn off the DSC, but not the ABS system. To do so might make them liable if a person skidded while braking, and crashed the car.
Also, they keep tight tabs on the wheel speeds for other reasons, and if they detect a strange condition, they have to assume a system has failed, and make the car "safe" to drive for inspection and repairs.

Now, if you simply want this behaviour to stop for a dyno test, there is a simple fix:
Unbolt the rear wheel speed sensors and tie them up out of the way.
They pass the startup self test, they do not detect any speed, and they match the front wheels in this.
This wil help a bit.
But, ultimately the ECU will tell by other means that the car is moving, and still eventually throw a fault.
So, can not tell the ABS unit that the wheels are not moving.
One has to tell it that ALL the wheels are moving at the same speed, and that is the speed at the rear wheels.
The rear sensors have to be in place and functional, the signal from it has to be passed to the inputs for the front wheels.
The signal has to be multiplexed from the rear to the front sensor lines to the ABS computer.
Then the ABS computer believes it is travelling down the road in a normal fashion. IT does not complain to the ECU, and the ECU has inputs from all it's data sources telling it that all is happening in a normal fashion.

How to do this, or course, is the trick.
We now know how to do this, but we are not saying how yet.

Hymee

iTrader: (1)

Maurice,

Yes - I had earlier posted that my crazy theory on disconnecting was wrong. Like I said - food for thought. Yes - Mazda obviously must re-configure the ECU on the engine dyno to allow this to happen, and they would certainly have the means to do it.

I have never experienced a CEL doing a burnout.

But more importantly - we have never experienced a CEL on the dyno. We have had ABS/DSC warning lights come on, but never, ever a CEL.

I have also never experienced any warning conditions on the strip.

It has been mentioned around here by others about sending the rear signals to the front, and that seem the most obvious option.

Since this is a forum for sharing of technical information, how about you share it with us?

Cheers,
Hymee.

PS - I still don't know what was wrong with what I said about the chassis dyno's though...

meteoro

I was reading Sport Car Compact, and they ran into a similar situation with the BMW M3. The computer does not allow for the car to redline if the front wheels are not moving at the same speed as the rear wheels. The car would not rev pass 6500 rpm's.
As a result SCC could not post dyno numbers for the comparison they were making.
BTW, they ran into the same situation with the porsche C4.
Mazda is not the only one who programs their ECU not to deliver maximum power if all the wheels are not spinning.

canzoomer

There is a chap in the UK who has asked me to send him a unit, so we should find out how effective this is over there in a couple of weeks or so.

canzoomer

I think he misunderstood.
On a 4 wheel dyno, the front wheels are on rollers tied to the rear rollers. They ALL turn.
Not many 4 wheel drive dynos out in the wild to be found.

If you run the car after teh ABS and DSC lights turn on it will eventually generate a check engine light. It takes 3 to 4 seconds to generate an ABS fault.
And about 20 seconds to generate a check engine after the ABS fault comes on.

If your runs are short enough, then it does not have time to do this.

OK, here is a simple hint on what is needed to make the system happy:

We are trying to accomplish a couple of things:

1) To pass power on self test, the Bosch ABS unit must detect 4 functioning sensors. The sensors are inductors. The inductance AND the resistance of the sensor circuits MUST be measured and matched by your fooler circuit.

2) It is best to leave one actual sensor active on a rear wheel, so that the other systems in the ECU "believe" the car is travelling.

3) You need to multiplex the pulses generated on that one real sensor to the other 3 sensor inputs to the Bosch unit.
Easiest way I know is by building a circuit using pulse transformers to take the one wheel sensor output and replicate it on the other 3.

The rest of the circuit design I will leave to your imagination.

Basically parts needed are:

6 pulse transformers, 6 pole, 3:1 configuration ( unless you can find some 4:1, I could not)

6 resistors - You are shooting for 1.3KOhm on each sensor pair.

3 inductor choke coils. You are replicating about .5 to 1 Henry of inductance.

Circuit voltage is about 150 millivolt

All sensors are common ground to the ABS controller, NOT chassis ground.

disconects and taps to connect to the wires in the harness just before the ABS controller unit plug.

If you know how to design a circuit that will be what you need to know.

Lock & Load

MAURICE

Hymee and others will see your information on correctly dynoing the RX8 as the BEST CHRISTMAS present to date.

Thanks ( HOPEFULLY NOW ALL THE RX8 MYSTERIES WILL BE EASIER TO UNRAVEL)

michael

Hymee

iTrader: (1)

Maurice,

Nice info, mate.

I think we got our "wires crossed" on the chassis dyno thing. The original post in this thread from Mazda talked about chassis dyno's being inacurate because of the way they measure power from building up inertia, and I was referring to modern chassis dyno's using a computer controlled electromagnetic brake to determine an actual torque reading.

A modern chassis dyno measures power at the wheels in exactly the same way as a modern engine dyno.

Anyway - it looks like the next supplier we need to find is the one who can sell us the OEM plugs/sockets used in the harness

Cheers,
Hymee.

miraclewhip

what is the best cat back exhaust for my 8